What will my 340 run? and what intake and carb?

Hey man I have a 340 in my duster. I like an eldebrock super victor intake and a good 750 carb be it holley or whatever you like I run a proform. I think that your gear choice is great for street and strip but if you are going to run strip more than street i would run a 456 or 488. When I got my car it had the same headers you are planing on running they are ok, kind of a wire burner and makes changing plugs a pain. I moved up to the 1 7/8 but they rap the frame (disadvantages to both). I think that you are close to right on what you are thinking it will run in the quarter. The one thing that I would tell you to do different than I did is to save for the good parts and not subsitute with something that won't get you what you want if performance is what you are after.